参数资料
型号: LTC1707CS8#TRPBF
厂商: Linear Technology
文件页数: 12/16页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 0.6A 8SOIC
标准包装: 2,500
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.8 V ~ 8.5 V
输入电压: 2.85 V ~ 8.5 V
PWM 型: 电流模式,混合
频率 - 开关: 35kHz ~ 350kHz
电流 - 输出: 600mA
同步整流器:
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
供应商设备封装: 8-SOIC
LTC1707
APPLICATIO S I FOR ATIO
Design Example
As a design example, assume the LTC1707 is used in a
single lithium-ion battery-powered cellular phone applica-
tion. The V IN will be operating from a maximum of 4.2V
down to about 2.85V. The load current requirement is a
maximum of 0.3A but most of the time it will be in standby
mode, requiring only 2mA. Efficiency at both low and high
load currents is important. Output voltage is 2.5V. With
this information we can calculate L using equation (1),
A 22 μ H inductor works well for this application. For best
efficiency choose a 1A inductor with less than 0.25 ?
series resistance.
C IN will require an RMS current rating of at least 0.15A at
temperature and C OUT will require an ESR of less than
0.25 ? . In most applications, the requirements for these
capacitors are fairly similar.
For the feedback resistors, choose R1 = 80.6k. R2 can then
be calculated from equation (2) to be:
( )( )
V OUT ? 1 ? OUT ?
R 2 = ? OUT ? 1 ? R 1 = 171 k ; use 169k
L =
1
f ? I L
? V ?
? V IN ?
(3)
? V ?
? 0 . 8 ?
Substituting V OUT = 2.5V, V IN = 4.2V, ? I L = 120mA and
f = 350kHz in equation (3) gives:
Figure 8 shows the complete circuit along with its effi-
ciency curve.
)(
)
? 1 ?
? = 24 . 1 μ H
L =
(
2 . 5 V ?
350 kHz 120 mA ?
2 . 5 V ?
4 . 2 V ?
C ITH
47pF
1
I TH
V REF
8
2
RUN/SS SYNC/MODE
7
100
C SS
0.1 μ F
3
V FB
LTC1707
V IN
6
V IN
2.85V TO
90
V IN = 3.6V
4
GND
SW
5
22 μ H*
R2
V OUT
2.5V
0.3A
4.5V
80
V IN = 4.2V
169k
1%
+
C OUT?
100 μ F
+
C IN??
22 μ F
70
R1
6.3V
16V
80.6k
1%
60
V OUT = 2.5V
L = 22 μ H
AVX TPSC107M006R0150
* SUMIDA CD54-220
?
?? AVX TPSC226M016R0375
1707 F08a
50
1
Burst Mode OPERATION
10 100
OUTPUT CURRENT (mA)
1000
1707 F08b
Figure 8. Single Lithium-Ion to 2.5V/0.3A Regulator from Design Example
12
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LTC1707IS8 功能描述:IC REG BUCK SYNC ADJ 0.6A 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V,1.5V,1.8V,2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP,10-MSOP(0.118",3.00mm 宽)裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘
LTC1707IS8#PBF 功能描述:IC REG BUCK SYNC ADJ 0.6A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V,1.5V,1.8V,2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP,10-MSOP(0.118",3.00mm 宽)裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘
LTC1707IS8#TR 功能描述:IC REG BUCK SYNC ADJ 0.6A 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V,1.5V,1.8V,2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP,10-MSOP(0.118",3.00mm 宽)裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘
LTC1707IS8#TRPBF 功能描述:IC REG BUCK SYNC ADJ 0.6A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V,1.5V,1.8V,2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP,10-MSOP(0.118",3.00mm 宽)裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘
LTC1707IS8PBF 制造商:Linear Technology 功能描述:DC-DC Converter Step-Down 2.85-8.5V SO8